Effects of non-paretic arm movements during bridge exercises on trunk muscle activity in stroke patients

[Purpose] The purpose of this study was to determine the effects of non-paretic arm movement during the bridge exercise on trunk muscle activity in stroke patients. [Participants and Methods] In total, 18 stroke patients were recruited. Surface EMG electrodes were attached over the trunk muscles (rectus abdominis, RA; internal oblique, IO; erector spinae, ES), and three kinds of bridge exercises were performed: 1) 'standard' bridge, 2) bridge with unilateral isometric arm flexion, and 3) bridge with unilateral isometric arm horizontal abduction. [Results] According to the activity of the trunk muscles measured during bridge exercises, only the IO and ES showed significantly greater muscle activity during bridges with isometric arm horizontal abduction and flexion than during the standard bridge. Additionally, comparison of the paretic and non-paretic sides showed that muscle activity was higher on the paretic side. [Conclusion] This study showed that, as an exercise to heighten the activity of the trunk muscles in stroke patients, bridge exercises with accompanying non-paretic arm flexion and horizontal abduction were more effective clinically than a standard bridge.